The present invention relates generally to optical waveguides (xe2x80x9cOWGsxe2x80x9d), and particularly to the composition of the coatings applied to the OWG.
The use of OWGs is becoming more and more prevalent in the telecommunications industry. This trend is definitely apparent in the area of reliable long-range communications. In the case of long-range communications, the entire distance between telephone company switching offices is actually numerous OWGs connected to each other in a series alignment. An individual strand of an OWG may be as long as fifty (50) kilometers or more.
The typical OWG utilized consists of a glass fiber with a primary and secondary coating. The secondary coating is an exterior coating of the primary coating.
As a matter of cost savings and practicality, a plurality of coated OWGs are bundled into a final fiber optics cable. This plurality of OWGs is installed at one time. The plurality of OWGs is typically in a loose tube or ribbon format. Each one of the OWGs is spliced and connected to another OWG in the series alignment described above. This splicing together of two OWGs, aligned in series, is repeated until the entire length of OWGs extends between one switching office to another switching office.
In installing the OWG in the cable format and splicing the various OWGs together, the identification of each individual strand of fiber is important. To assist in the identification, each OWG is typically inked. Some OWGs have colored coatings that can be used for identification. The identification mechanism of inking may be color, a pattern applied to the OWG, or any other suitable technique to quickly identify objects to be spliced together.
Each OWG is extensively handled at each junction where two cables are spliced together. The adherence of the ink to the coated OWG is very important at this point. Typical problems that may be encountered include peeling, flaking, or pitting. Also the ink should not delaminate from the coating.
One aspect of the present invention is a coated OWG. The coated OWG includes an OWG having a first coating encompassing the OWG. The first coating has at least one functional group that is selected from a group consisting of an acidic group or a basic group. The coated OWG also includes a second coating having at least one functional group. The second coating functional group is a basic group when the first coating functional group is an acidic group. Alternatively, the second coating functional group is an acidic group when the first coating functional group is a basic group. The second coating is bonded to the first coating. The second coating may also include an ink. This aspect of the invention may also include additional adjacent coatings in which the acid/base character of each individual coating alternates between the respective adjacent coatings.
Another aspect of the present invention includes either the first or second coating having the acidic functional group in a greater amount than stoichiometric amount of the basic functional group.
A further aspect of the invention includes a method of coating an OWG. The method includes applying the first coating having at least one functional group that is selected from a group consisting of an acidic group or a basic group to the OWG. The method also includes applying the second coating having at least one functional group to the first coating, thereby bonding the second coating to the first coating. The second coating functional group is a basic group when the first coating functional group is an acidic group. Alternatively, the second coating functional group is an acidic group when the first coating functional group is a basic group.
An additional aspect of the invention includes a method of controlling optical waveguide inter coating adhesion. Acid/base character is alternated between a plurality of adjacent coating layers.
The coated OWG of the invention results in a several advantages over the prior art. For example, an OWG coated in accordance with the invention has exhibited improved adhesion between the first coating and the second coating. Consequently, the second coating of the invention has exhibited improved abrasion resistance and is less susceptible to peeling, flaking, or pitting.
Another advantage of the invention is an enhancement in the total adhesion strength of the coatings. The advantages also include high molecular adhesion between the coatings which include the bonded functional groups as well as increased adhesive strength. This may also be used to control the adhesion between coatings by means of acid/base interaction.
Additional features and advantages of the invention will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the invention as described herein, including the detailed description which follows, the claims, as well as the appended drawings.
It is to be understood that both the foregoing general description and the following detailed description are merely exemplary of the invention, and are intended to provide an overview or framework for understanding the nature and character of the invention as it is claimed. The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate various embodiments of the invention, and together with the description serve to explain the principles and operation of the invention.